Hot-air furnace.



PATENTED JULY 4, 1905.

J' LEPPLA HOT AIB, FURNACE..

APPLIUATION FILED MAE. s, 1905.

'Patented July 4t, 1.905.

atterri Ustica JUHN LEPPLA, UF KNUBVVILLE BURUUGH, PENNSYLVANIA.

lwl til llt l W li tl lift llt it tit t SPECFICATIKON forming' part of Letters Patent No. 793,943, dated July 4t, 1905,

Application liled March 8,1905. Serial N0. 249,051.

lie it known that l, Jeun Larrea, a citizen ol the United States oli' America, residing at ,lnoxsville borough, in the county ot Alle ghen y and State el .l;ennsylvania, have invented certain new and useiul lnnjn'ovements in liet-Air Furnaces, o'll which the following is a peciiication, reference being had therein to the accom panying drawing.

rllhis invention has relation to hot-air furnaces, and relates in particular to Vfurnaces of this class in which gas is used as a luel.

'l`he object of the invention is to provide a hot-air VFurnace wherein the air will be heated. by the consumption o1 a minimum amount oli gas.

Briefly described, my invention comprises an outer easing, a series of cylindrical drums mounted in the casing and in communication with one another, the drums being' disposed one over the other and of gradually-decreas ing size from the lowerlnost to the uppermost drum, a series el" cone-shaped crnnlnistiontubes communicating with the lowermost drum, and a gas-eonduit which disposed be' neath the lower ends oi the comlnlstioirtubes and provided with a supply-pipe and with a series ol" burners, one of which projects into each combustion-tube.

Certain details in the construction and com hination ot parts will he hereinafter YFully set forth and claimed. v

lln the accoi'npanying drawing the single iigure is a sectional perspective view taken on the vertical plane extending through the center oit' a furnace constructed according to my improvement.

in the drawing, 1 designates the exterior casing, which is of cylindrical form and rests upon a iioor, this casing being made of any suitable materialws uch, for instance, as heavy sheet metal. The casing 1 is provided with a number of holes 2 near its lower edge,'and just above the tops oi these holes .i mount a horizontal partition 3, which is provided with a central orifice 4t and a plurality)T oi holes 5, the latter being disposed in a circle n zar the edge of the partition 3. Below the partition 3 a gas-eonduit 6 is arranged, being mounted on legs 7 7 and gas is supplied to this con duit by means o1 a gas-supply pipe 8, which is furnished with a valve 9, Afrom which valve branches 10 10 lead to the conduit 6. Upon top o1 the partition 3 a plurality oi' coneshaped combustion tubes 11 are mounted, their number being dependent upon the size of the Vfiin'nace and the desired heating' capacity ot the same 'lhese cone-shaped combustiontubes are mounted over the holes 5 5 and are lixed in position in any suitable manner upon the partition 3, and their upper ends 12, which are cylindrical in term, project into a large cylindrical sheet-metal drum 13 and extend nearly to the top thereof. The drum 1? may be supported upon the combustion-tubes, as shown in the d rawing, and a series ol|` conduits 14 extend vfrom near the bottom of the drum 13, through the top thereof and through the bottom ot' a similar but smaller drum 15 to near the top oli the last-named drum, and a series oi similar but smaller conduits 16 extend lrom near the bottom et the drum 15, through the top thereol and through the bottom oi a still smaller drum 17 and. to near the top ol the last-named drum, which latter carries a centrally-arranged smoke-pipe 18, extending Afrom near the bottom o1 the drum 17 through the top ol the casing 1. The casing 1 has a number oil holes 19 in its top and these holes constitute entrances to the hot-air 'fines 20, ot which any desired number are provided. A number oi? burners Q1 are mounted upon vertical pipes 22, carried by the gas-conduit 6, and one or' these is located in each o1 the combustion-tubes 11.

ihe furnace being constructed as described and shown operates as follows: Gras being' supplied to the conduit (i hy opening the gas-valve 9 will `llow tothe burners 21 and being' ignited burn in the combustion-tu hes 11, and the products of combustion will :ilcw into the drum 13, thence to drum 15, thence to drum 17, and out ot' the furnace through the smolre-pipe 18, passing, as indicated hy the arrows, successiveiy through the conduits 14: and 16. Air is admitted to the casing 1 through the epenings 2, a part oi' the air going to supply oxygen to the gas in the combustion-tubes and the rest ot the air .flowing through the opening t in the partition 3 and impinging against and passing around the combustion-tubes 11, and the bottom of the drum 13 will be heated and will How upwardly through the casing and will contact with the conduits 14 and 16 and the drums 15 and 17 and inally emerge in a highly-heated condition through the hot-air pipes 2O 20.

It will be noted, and this is an important feature of my invention, that the drums decrease in size from the lowermost to the uppermost drum, and that therefore the casing being' of equal diameter throughout that portion in which the drums are located the air-space in the casing gradually increases in size from near the bottom to toward the top of the casing, and therefore the air as it becomes heated by its successive contact with those portions of the furnace through which the products of combustion pass will have an opportunity to expand, and there will therefore be less tendency for this expansion of the air to force it into the hot-air pipes than if the capacity 0f the casing was the same throughout.

lVhile I have shown and described my improved furnace as being provided with but three of the heating-drums, I wish it to be understood that a greater or less number of the4 same may be employed without departing from the spirit and scope of the invention.

Another feature of particular ,importance in my improvement is that the combustiontubes are cone-shaped and that the conduits 16 are smaller than the conduits 14 and that the latter are somewhat smaller than the upper portions 12 of the combustion-tubes. This construction retards the passage of the products of combustion through the furnace with the resultant effect that the maximum amount of heat is imparted to the air flowing through the furnace, thus effecting a great economy ,in the consumption of fuel.

That I claim, and desire to secure by Letters Patent, is

1. In a hot-air furnace, the combination of a casing having inlet-openings, hotsair pipes connected to said casing, a horizontal partition mounted in the casing, a gas-cond uit arranged below said partition, a gas-pipe connected to said conduit, a plurality of cone-shaped tubes mounted on said partition, gas-burners carried by said conduit and arranged within said cone-shaped tubes, a plurality of communieating drums arranged in said casing, said drums being of different sizes and one of said drums communicating with said cone-shaped tubes, the smallest drum being arranged at the upper end of the casing, and a smoke-pipe connected to said smallest drum.

2. In a hot-air fu rnace, the combination with a casing, a horizontal partition in said casing, cone-shaped combustion-tubes mounted on said partition, gas-burners arranged at the lower ends of the combustion-tubes, and a plurality of drums arranged in the casing and communicating with said combustion-tubes and with one another.

3. In a hot-air furnace,the combination with a casing, a plurality of communicating drums of varying sizes and cylindrical form arranged in the casing one over the other, the smallest drum being at the top of the casing and the largest drum near the bottom of the same, combustion tubes extending downwardly from the lowest drum and gas-burners arranged at the lower ends of said combustiontubes.

In testimony whereof I aIiX my signature in the presenceof two witnesses.

JOHN LEPPLA. YWitnesses:

K. II. BUTLEN, E. E. POTTER. 

